(a) Field of the Invention
The present invention relates to a new structure for an electric pump, particularly to an electric pump having dual pistons device, pressure switch and special designed channels so that the air discharging and sucking operation are continuous.
(b) Description of the Prior Art
Pumps provide the means of accepting a mechanical power input and converting it to an equivalent amount of fluid power, fluid moving under pressure. According to a survey, air pumps can generally be categorized into several types: manual or foot air pumps, simple electric pumps, and electric motor or diesel engine driven air compressors. Among the different types of pumps, the manual air pump can often be seen in our daily life. It is recognized that the simple manual air pump is handy to be used everywhere. However, this kind of air pump has a limited power and the vigorous pumping is tedious. The electric motor or diesel engine powered air compressor is convenient to be used for higher capacity. However, its bulky physical size is not handy to be carried or moved around and this is a disadvantage- The introduction of the simple electric pump seems to have overcome the above disadvantage. It is small in size and is convenient to be carried around. Electric power is all that is needed to operate the simple electric pump. For these reasons, electric pumps are widely used in automobiles, boats and are becoming a necessity in our daily lives. The inventor, after several years of research in the related field, has found that certain drawbacks still exist in the simple electric pumps:
1. The operation of a simple electric pump uses a single piston to reciprocate so as to function as a pump. On the downstroke of the piston, air is forced to discharge. On the upstroke a suction is created under the piston. However, a single piston cannot maintain the continuous operation of sucking and discharging, it can only reciprocate fast enough so that the suction and discharge appears to be continuous. Thus, the speed of air filling is slower. In addition, the air loss and the reciprocating frictional loss are higher due to the discontinued stroking of the piston. Hence, the air flow capacity and the pumping efficiency are low.
2. The capacity to be pumped using the simple electric pump depends of the user's experience. A device to be pumped with a critical pressure requirement is not protected against over pumping.
3. Most of the simple electric pumps create a high frequency vibration during operation. The base of such electric pumps contact with the ground directly and can easily cause damage to the pump assembly.
Because of the aforesaid disadvantages, the inventor has spent a considerable amount of time to overcome those drawbacks. Hence, a new structure for an electric pump having a dual pistons, pressure switch, specially constructed channels and vibration-proof leg is developed.